Tkinter updating label fails with "AttributeError: 'Frame' object has no attribute 'label1' "

I'm trying to put together my first tkinter application, showing values recieved from Arduino serial port, I successfully managed to make console application, but I'm novice in GUI.

raw0 is string with 'NR'
raw 1 - 4 are int compatible values
raw5 is string 'EOR'

here is my code:

#!/usr/bin/python3
import tkinter as tk
import tkinter.ttk as ttk
import serial
Arduino = serial.Serial('/dev/ttyUSB3', '115200', timeout=1)
print('Connection is working')
value1 = 0
value2 = 0
value3 = 0
value4 = 0
class App:
def readdata(self):
Arduino.write(bytes('n', 'utf-8'))
for x in range(0, 6):
globals()['raw%s' % x] = Arduino.readline().decode().strip()
self.value1 = int(raw1)
self.value2 = int(raw2)
self.value3 = int(raw3)
self.value4 = int(raw4)
App.changelabels(self.mainframe)
def changelabels(self):
label1.config(text=self.value1.get())
def __init__(self, master=None):
# build ui
self.appwindow = tk.Tk() if master is None else tk.Toplevel(master)
self.appwindow.configure(height=240, width=320)
self.appwindow.minsize(320, 240)
self.mainframe = ttk.Frame(self.appwindow)
self.mainframe.configure(height=240, width=320)
label1 = ttk.Label(self.mainframe)
self.value1 = tk.IntVar()
label1.configure(textvariable=self.value1)
label1.grid(column=1, row=0)
label2 = ttk.Label(self.mainframe)
self.value2 = tk.IntVar()
label2.configure(textvariable=self.value2)
label2.grid(column=1, row=1)
label3 = ttk.Label(self.mainframe)
self.value3 = tk.IntVar()
label3.configure(textvariable=self.value3)
label3.grid(column=1, row=2)
label4 = ttk.Label(self.mainframe)
self.value4 = tk.IntVar()
label4.configure(textvariable=self.value4)
label4.grid(column=1, row=3)
self.text1 = ttk.Label(self.mainframe)
self.text1.configure(text='Value1: ')
self.text1.grid(column=0, row=0)
self.text2 = ttk.Label(self.mainframe)
self.text2.configure(text='Value2: ')
self.text2.grid(column=0, row=1)
self.text3 = ttk.Label(self.mainframe)
self.text3.configure(text='Value3: ')
self.text3.grid(column=0, row=2)
self.text4 = ttk.Label(self.mainframe)
self.text4.configure(text='Value4:  ')
self.text4.grid(column=0, row=3)
progressbar1 = ttk.Progressbar(self.mainframe)
progressbar1.configure(orient="horizontal")
progressbar1.grid(column=2, row=0)
progressbar2 = ttk.Progressbar(self.mainframe)
progressbar2.configure(orient="horizontal")
progressbar2.grid(column=2, row=1)
progressbar3 = ttk.Progressbar(self.mainframe)
progressbar3.configure(orient="horizontal")
progressbar3.grid(column=2, row=2)
progressbar4 = ttk.Progressbar(self.mainframe)
progressbar4.configure(orient="horizontal")
progressbar4.grid(column=2, row=3)
self.refresh = ttk.Button(self.mainframe)
self.refresh.configure(text='Refresh')
self.refresh.configure(command=self.readdata)
self.refresh.grid(column=1, row=4)
self.mainframe.pack(side="top")
# Main widget
self.mainwindow = self.appwindow
def run(self):
self.mainwindow.mainloop()
if __name__ == "__main__":
app = App()
app.run()

Thank you very much and have a nice day!

I'm trying to update labels (label1-4) with variables stored in value1-4, but I'm unable to do so, mostly because I don't know how to approach labels correctly.
I've tried various ways how to approach this, but I've failed every time. Is anybody willing to kick me into right direction?

Change label1 = ttk.Label(self.mainframe) to self.label1 = ttk.Label(self.mainframe) and similarly prefix all references to label1 with self everywhere else it's used. That way, all methods that are members of your App class (and have access to self) will have access to self.label1